Stephanie Fuller

Successful Use of the Total Artificial Heart in the Failing Fontan Circulation

Typical left ventricular assist devices are often ineffective for the failing Fontan circulation. We report the first successful use of a total artificial heart as a bridge to transplant in a patient who had previously undergone a Fontan operation.

Time to surgery and preoperative cerebral hemodynamics predict postoperative white matter injury in neonates with hypoplastic left heart syndrome

OBJECTIVE Hypoxic-ischemic white mater brain injury commonly occurs in neonates with hypoplastic left heart syndrome (HLHS). Approximately one half of HLHS survivors will exhibit neurobehavioral symptoms believed to be associated with this injury, although the exact timing of the injury is unknown. METHODS Neonates with HLHS were recruited for pre- and postoperative monitoring of cerebral oxygen saturation, cerebral oxygen extraction fraction, and cerebral blood flow using 2 noninvasive optical-based techniques: diffuse optical spectroscopy and diffuse correlation spectroscopy. Anatomic magnetic resonance imaging was performed before and approximately 1 week after surgery to quantify the extent and timing of the acquired white matter injury. The risk factors for developing new or worsened white matter injury were assessed using uni- and multivariate logistic regression. RESULTS A total of 37 neonates with HLHS were studied. On univariate analysis, neonates who developed a large volume of new, or worsened, postoperative white matter injury had a significantly longer time to surgery (P=.0003). In a multivariate model, a longer time between birth and surgery, delayed sternal closure, and greater preoperative cerebral blood flow were predictors of postoperative white matter injury. Additionally, a longer time to surgery and greater preoperative cerebral blood flow on the morning of surgery correlated with lower cerebral oxygen saturation (P=.03 and P=.05, respectively) and greater oxygen extraction fraction (P=.05 for both). CONCLUSIONS A longer time to surgery was associated with new postoperative white matter injury in otherwise healthy neonates with HLHS. The results suggest that earlier Norwood palliation might decrease the likelihood of acquiring postoperative white matter injury.

Emerging Research Directions in Adult Congenital Heart Disease: A Report From an NHLBI/ACHA Working Group.

Congenital heart disease (CHD) is the most common birth defect, affecting about 0.8% of live births. Advances in recent decades have allowed >85% of children with CHD to survive to adulthood, creating a growing population of adults with CHD. Little information exists regarding survival, demographics, late outcomes, and comorbidities in this emerging group, and multiple barriers impede research in adult CHD. The National Heart, Lung, and Blood Institute and the Adult Congenital Heart Association convened a multidisciplinary working group to identify high-impact research questions in adult CHD. This report summarizes the meeting discussions in the broad areas of CHD-related heart failure, vascular disease, and multisystem complications. High-priority subtopics identified included heart failure in tetralogy of Fallot, mechanical circulatory support/transplantation, sudden cardiac death, vascular outcomes in coarctation of the aorta, late outcomes in single-ventricle disease, cognitive and psychiatric issues, and pregnancy.

Long-term functional health status and exercise test variables for patients with pulmonary atresia with intact ventricular septum: A Congenital Heart Surgeons Society study

BACKGROUND A bias favoring biventricular (BV) repair exists regarding choice of repair pathway for patients with pulmonary atresia with intact ventricular septum (PAIVS). We sought to determine the implications of moving borderline candidates down a BV route in terms of late functional health status (FHS) and exercise capacity (EC). METHODS Between 1987 and 1997, 448 neonates with PAIVS were enrolled in a multi-institutional study. Late EC and FHS were assessed following repair (mean 14 years) using standardized exercise testing and 3 validated FHS instruments. Relationships between FHS, EC, morphology, and 3 end states (ie, BV, univentricular [UV], or 1.5-ventricle repair [1.5V]) were evaluated. RESULTS One hundred two of 271 end state survivors participated (63 BV, 25 UV, and 14 1.5V). Participants had lower FHS scores in domains of physical functioning (P < .001) compared with age- and sex-matched normal controls, but scored significantly higher in nearly all psychosocial domains. EC was higher in 1.5V-repair patients (P = .02), whereas discrete FHS measures were higher in BV-repair patients. Peak oxygen consumption was low across all groups, and was positively correlated with larger initial tricuspid valve z-score (P < .001), with an enhanced effect within the BV-repair group. CONCLUSIONS Late patient-perceived physical FHS and measured EC are reduced, regardless of PAIVS repair pathway, with an important dichotomy whereby patients with PAIVS believe they are doing well despite important physical impediments. For those with smaller initial tricuspid valve z-score, achievement of survival with BV repair may be at a cost of late deficits in exercise capacity, emphasizing that better outcomes may be achieved for borderline patients with a 1.5V- or UV-repair strategy.

Long-term survival after the Fontan operation: Twenty years of experience at a single center

Objective: Existing studies of patients palliated with the Fontan operation are limited by heterogeneous patient populations and incomplete follow‐up. This study aimed to describe long‐term post‐Fontan survival in a modern patient cohort. Methods: All 773 patients who underwent a first Fontan operation at our institution between 1992 and 2009 were reviewed. The primary outcome was the composite endpoint of Fontan takedown, heart transplantation, or death before 2013. Results: Follow‐up rate was 99.2%. Survival with intact Fontan circulation was 94% at 1 year (95% confidence interval [95% CI], 92%‐95%), 90% at 10 years (95% CI, 88%‐92%), 85% at 15 years (95% CI, 82%‐88%), and 74% at 20 years (95% CI, 67%‐80%). Distinct risk factors were identified for early (≤1 year) and late composite outcomes. Independent risk factors for early outcome included prolonged pleural drainage (hazard ratio [HR], 4.4; P < .001), intensive care unit stay >1 week (HR, 2.4; P < .001), Fontan before 1997 (HR, 3.3; P < .001), preoperative atrioventricular valve regurgitation (HR, 2.0; P < .001), and longer crossclamp time (HR, 1.3 per 10 minutes; P < .001). Late outcome was predicted by atrioventricular valve regurgitation prior to Fontan (HR, 2.0; P ≤ .001), and post‐Fontan ICU stay >1 week (HR, 2.4; P < .001). Conclusions: Long‐term mortality after Fontan operation remains substantial. Risk factors for death or loss of Fontan circulation differ between the early and late postoperative periods. Long‐term survival has not improved appreciably over the last decade, suggesting that alternatives to the Fontan are warranted.

Mechanical embolectomy for ischemic stroke in a pediatric ventricular assist device patient

The reported incidence of cerebral embolic or hemorrhagic complications related to mechanical circulatory support in children is high, even while subjects are managed with aggressive antithrombotic therapy. The safety and utility of endovascular treatment for stroke in the pediatric VAD population has not been established in the published literature. We describe a nine‐yr‐old patient on BiVAD support who experienced threatened AIS on two separate occasions. He was treated successfully via mechanical embolectomy on both occasions and survived to transplantation with minimal neurologic deficits.

Long-term atrial and ventricular epicardial pacemaker lead survival after cardiac operations in pediatric patients with congenital heart disease

BACKGROUND Multiple cardiac operations and resultant myocardial scarring have been implicated in the overall reduced performance of epicardial pacing systems in patients with congenital heart disease (CHD). OBJECTIVE The aim of the study is to evaluate long-term permanent epicardial pacing lead survival in patients with CHD who had epicardial lead placement in association with surgical repair or palliation. METHODS A retrospective review of patients who had implantation of epicardial pacing systems between January 1984 and June 2010 was conducted. Inclusion criteria were as follows: (1) presence of CHD and (2) cardiac operation(s) concomitant with or before initial permanent epicardial lead implantation. Patients were divided into 2 anatomical groups: single ventricle (SV) and biventricle (Bi-V). RESULTS Epicardial leads were implanted in 663 patients during the study period. One hundred fifty-five patients (76 SV [49%] and 79 Bi-V [51%]) were included, resulting in 259 leads and 946 lead-years of follow-up. There were 2 deaths and 8 infections attributable to pacemaker placement. Overall atrial lead survival at 1, 2, 5, and 10 years (99%, 93%, 83%, and 72%) was comparable with ventricular lead survival (97%, 90%, 74%, and 60%) (P = .540) and was also similar between SV and Bi-V patients. Cox regression analysis demonstrated that SV palliation and an earlier era of lead implantation (1984-1999) was significantly associated with ventricular, but not atrial, lead malfunction. CONCLUSION Epicardial leads had acceptable longevity despite cardiac operations for complex CHD, suggesting the long-term reliability of this pacing method.

Lung transplant waitlist mortality: height as a predictor of poor outcomes.

The LAS was designed to minimize pretransplant mortality while maximizing post‐transplant outcome. Recipients <12 are not allocated lungs based on LAS. Waitlist mortality has decreased for those >12, but not <12, suggesting this population may be disadvantaged. To identify predictors of waitlist mortality, a retrospective analysis of the UNOS database was performed since implementation of the LAS. There were 16 973 patients listed for lung transplant in the United States; 12 070 (71.1%) were transplanted, and 2498 (14.7%) patients died or were removed from the wait list. Significantly more pediatric patients died or were removed compared with adults (22.0% vs. 14.4%, p < 0.01). In multivariate analysis, in addition to higher LAS at time of listing (adj. HR1.058, 1.055–1.060), shorter height (1.008, 1.006–1.010), male gender (1.210, 1.110–1.319), and requiring ECMO (1.613, 1.202–2.163) were associated with pretransplant mortality. Post‐transplant survival was not affected by height. The current age cutoff may impose limitations within the current lung allocation system in the United States. Height is an independent predictor of waitlist mortality and may be a valuable factor for the development of a comprehensive lung allocation system.

Skeletal muscle and plasma concentrations of cefazolin during cardiac surgery in infants

OBJECTIVE To describe the pharmacokinetics and tissue disposition of prophylactic cefazolin into skeletal muscle in a pediatric population undergoing cardiac surgery. METHODS The subjects included 12 children, with a median age of 146 days (interquartile range, 136-174) and median weight of 5.5 kg (interquartile range, 5.2-7.3) undergoing cardiac surgery and requiring cardiopulmonary bypass with or without deep hypothermic circulatory arrest. Institutional cefazolin at standard doses of 25 mg/kg before incision and 25 mg/kg in the bypass prime solution were administered. Serial plasma and skeletal muscle microdialysis samples were obtained intraoperatively and the unbound cefazolin concentrations measured. Noncompartmental pharmacokinetic analyses were performed and the tissue disposition evaluated. RESULTS After the first dose of cefazolin, the skeletal muscle concentrations peaked at a median microdialysis collection interval of 30 to 38.5 minutes. After the second dose, the peak concentrations were delayed a median of 94 minutes in subjects undergoing deep hypothermic circulatory arrest. Skeletal muscle exposure to cefazolin measured by the area under concentration time curve 0-last measurement was less in the subjects who underwent deep hypothermic circulatory arrest than in those who received cardiopulmonary bypass alone (P = .04). The skeletal muscle concentrations of cefazolin exceeded the goal concentrations for methicillin-sensitive Staphylococcus aureus prophylaxis; however, the goal concentrations for gram-negative pathogens associated with surgical site infections were achieved only 42.1% to 84.2% and 0% to 11.2% of the intraoperative time in subjects undergoing cardiopulmonary bypass alone or deep hypothermic circulatory arrest, respectively. CONCLUSIONS This cefazolin dosing strategy resulted in skeletal muscle concentrations that are likely not effective for surgical prophylaxis against gram-negative pathogens but are effective against methicillin-sensitive S aureus in infants undergoing cardiac surgery.

Tetralogy of Fallot and Pulmonary Valve Replacement: Timing and Techniques in the Asymptomatic Patient

An increasing number of survivors of congenital heart disease will require repeat surgical intervention. In the tetralogy of Fallot population, the primary indication is for pulmonary valve replacement secondary to pulmonary regurgitation. Although pulmonary valve disruption during repair is initially well tolerated, by the second decade following repair, patients develop increased right ventricular size with potentially decreased function. It is now well accepted that patients experiencing symptoms of heart failure secondary to chronic pulmonary insufficiency undergo pulmonary valve replacement. However, in the asymptomatic population, indications and timing of valve replacement are less clear. This article examines the current literature and presents guidelines regarding pulmonary valve replacement in the asymptomatic patient. Also, in the current era of percutaneous valve replacement, certain technical considerations should be given toward valve replacement and are discussed as well.